Evaluating the Power-law Response for Tin Dioxide Nanostructured Sensors in the Presence of Oxygen and Reducing Gases

P. M. DESIMONE; F. SCHIPANI; R. PROCACCINI; D. A. MIRABELLA; C. M. ALDAO

SENSORS AND ACTUATORS B-CHEMICAL

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2022

0925-4005

It is well known that the electrical conductance of gas sensors, based on polycrystalline metaloxidesemiconductors, obeys a power-law response with a gas pressure as p-. The value of theexponent which determines the sensor sensitivity,is regularly derived resorting to the massaction law applied to proposed reactions at the surface of the semiconductor. Conversely, basedon the experimentally observed values of γ for different gases, researchers also determine thepossible species present at the surface and the reactions that can occur. In line with thisapproach, we present experimental results, for oxygen and a typical reducing gas, which confirmthat oxygen is adsorbed/desorbed neutral, as predicted by the Wolkenstein theory ofchemisorption, and ionosorbs doubly charged.